Orthopedic cast having protective sleeve

ABSTRACT

An orthopedic cast which is air permeable to permit ventilation to the surface of the skin, and which is non-wetting whereby the cast is quick to dry upon exposure to water. The cast includes a protective sleeve comprising a relatively open, air permeable, non-wetting fabric, and an overlying immobilizing structure which is also air permeable and non-wetting. The yarns of the sleeve fabric may be intimately admixed with a bacteriostatic agent to retard the growth of micro-organisms, and they may be texturized to provide extra body.

United States atet [191 Woodall, Jr.

[ 1 ORTHOPEDIC CAST HAVING PROTECTIVE SLEEVE [75] Inventor: Hubert C. Woodall, Jr.,

Winston-Salem, N.C.

[73] Assignee: Carolina Narrow Fabric Company,

Winston-Salem, NC.

22 Filed: Dec. 29, 1969 21 Appl. No.1 888,441

[52] US. Cl. 128/90; 128/156; 66/195 [51] Int. Cl. A61f 13/04 [58] Field of Search 128/90, 82, 83, 156; 66/202, 195; 106/15 [56] References Cited UNITED STATES PATENTS 2,919,200 12/1959 Dubin et a1. 106/15 3,069,885 12/1962 Cooper et a1. 66/195 3,097,644 7/1963 Parker 128/89 X 3,299,890 1/1967 Parker 128/156 3,375,684 4/1968 Page 66/202 3,421,501 l/1969 Beightol 128/90 3,490,444 l/1970 Larson 128/90 1 May 13, 1975 12/1970 Garcia 128/90 X OTHER PUBLICATIONS Glass Plastic Cast by R. Anderson et al., The American Journal of Surgery, Vol. LXIX, No. 3, 1945, p. 299305.

Primary ExaminerRichard A. Gaudet Assistant E.\'aminer-J. Yasko Attorney, Agent, or Firm-Parr0tt, Bell, Seltzer, Park & Gibson 4 Claims, 6 Drawing Figures PATENIE HAY] 31975 IN VENTOR I L) L A b w W 6 m E B u H ATTORNEY ORTHOPEDIC CAST HAVING PROTECTIVE SLEEVE The present invention relates to an orthopedic cast comprising a protective sleeve and a surrounding hard, rigid, immobilizing structure. More particularly, the invention relates to an air permeable and non-wetting orthopedic cast which permits air ventilation to the skin of a wearer and is quick drying upon exposure to water.

In applying a conventional plaster of paris cast, it is standard practice to first wrap the body member with a cotton bandage to provide a soft protective liner. Next, a plaster of paris bandage is wet and applied over the cotton bandage to form the immobilizing structure. Generally, the cotton bandage is treated with a water repellent material, such as paraffin wax or polyethylene film, to prevent water from penetrating the cotton bandage and reaching the skin.

While plaster of paris casts of the above type are in common usage, they possess many undesirable characteristics. For example, they are notoriously messy to apply, they are heavy and difficult to keep clean, and they will deteriorate when wet. Also, the skin of the patient often becomes wet during application in spite of the above precautions, and such wetting tends to irritate the skin. In addition, since the cast is impermeable to the passage of air and water vapor, body perspiration will cause the cotton bandage to be continuously moist thereby inducing skin irritation and producing bacterial growth and an unpleasant odor.

New orthopedic cast systems have recently been proposed wherein a resin impregnated fabric tape is utilized to form the immobilizing structure. In this type system, the body member is preferably first covered with a protective sleeve, and an initially flexible resin impregnated tape is positioned to overlie and surround the body member. The resin is then cured, for example by exposure to heat or ultraviolet light, causing the tape to be set into a hard lightweight structure.

While the latter resin cast system is an improvement over the plaster of Paris system, it has been found that the protective sleeve still tends to entrap moisture against the skin and cause skin infection and/or irritation. Also, the outer immobilizing structure is not sufficiently permeable to permit the passage of ventilating air to the protective sleeve and skin to relieve the buildup of perspiration.

Accordingly, it is an object of the present invention to provide an orthopedic cast comprising a protective sleeve and a surrounding immobilizing structure wherein both the sleeve and immobilizing structure are air permeable to permit ventilation tothe surface of the skin.

It is also an object of the present invention to provide an orthopedic cast wherein both the sleeve and immobilizing structure are substantially non-wetting such that the cast will not absorb moisture or perspiration. Also, the cast will be quick drying if it should become wet.

It is a further object of the present invention to provide a protective sleeve for an orthopedic cast which is resistant to bacterial growth. In this regard, it is an object of this invention to fabricate the sleeve from a yarn capable of being intimately admixed with a bacteriostatic agent.

It is an additional object of this invention to provide a protective sleeve which is fabricated from a yarn capable of being easily textured or bulked to provide a soft cushioned fabric.

These and other objects and advantages of the present invention are achieved in the embodiment illustrated herein by the provision of an orthopedic cast characterized by air permeability and non-wettability and comprising an inner sleeve positioned about a portion of the body of a wearer and which comprises a relatively open, air permeable, non-wetting fabric, and a rigid, lightweight, air permeable, non-wetting immobilizing structure positioned over the sleeve. The yarns of the sleeve fabric may, if desired, be intimately admixed with a bacteriostatic agent to retard the growth of micro-organisms, and they may be textured to provide extra body and a desirable softness of hand.

Some of the objects and advantages of the invention having been stated, others will appear as the description proceeds.

FIG. 1 illustrates the protective sleeve of the orthopedic cast of the present invention in position about the forearm of a patient;

FIG. 2 illustrates a method of applying a resin impregnated cast material to the forearmof a patient to form one embodiment of an orthopedic cast of the present invention;

FIG. 3 is a schematic illustration of a warp knit fabric suitable for the fabric used in the orthopedic cast material and wherein the chain stitched yarns are interconnected by three laid-in yarns to produce a resilient,

relatively open textile;

FIG. 4 is a schematic illustration of a similar warp knit fabric suitable for the fabric used in the orthopedic cast material and wherein a single laid-in yarn extends between four of the interconnected chain stitches;

FIG. 5 is a schematic illustration of a weft or circular knit fabric suitable for use in conjunction with the protective sleeve of the present invention, and

FIG. 6 is a schematic illustration of a warp knit construction which is also suitable for use in the protective sleeve.

The manner of applying an orthopedic cast which embodies the teachings of the present invention is illustrated in FIGS. 1 and 2. In FIG. 1, an inner protective sleeve 10 is shown positioned about the forearm of the patient. As illustrated, the sleeve 10 is in the form of a tubular member or stockinet, but it will be apparent that the sleeve could take other forms, such as for example an elongated strip or bandage which may be wrapped about the arm.

Once the sleeve 10 is in proper position, an orthopedie cast material 12, comprising for example a glass fiber fabric impregnated with a resin, is wrapped about the arm and over the protective sleeve 10 in a manner similar to the application of an elastic-type bandage. Typically, the orthopedic cast material 12 may be prepared for commercial use in 9 foot rolls, and in l, 2, 3, or 4 inch widths. Selection of the particular width varies with the type of cast being applied. The material 12 is highly flexible, and may be easily folded, twisted, tucked, or spread to conform to the irregular contours of the patients anatomy. Usually, four or five superposed layers or thicknesses are adequate, but additional layers may be employed in the case of larger casts. When the material 12 is in place, the resin in the material is cured (e.g., by exposure to heat or ultraviolet light) causing the layers of the material 12 to harden and adhere together into a rigid, lightweight, immobilizing structure.

In accordance with one embodiment of the present invention, the fiber fabric used in the orthopedic cast material 12 is relatively open and air permeable and comprises interlaced glass fiber yarns. Obviously, a wide variety of fabric constructions could be employed to provide these desired characteristics in the finished fabric. As examples of knitted constructions possessing these characteristics, referencx is made to FIG. 3 showing a warp knitted construction 20 wherein the chain stitched yarns 22 are interconnected by three laid-in yarns 24, and to FIG. 4 showing a similar warp knitted construction 30 wherein a single laid in yarn 32 extends between three of the interconnected chain stitches 34. Further details relating to the specific construction of the material 12 may be obtained by reference to the copending application of John L. Nisbet and Hubert C. Woodall, Jr., Ser. No. 888,447, filed concurrently herewith, and entitled Glass Fabric and Method of Forming Same.

The glass fiber fabric of the material 12 may be impregnated with a suitable curable resin, such as for example those specifically set forth in the patent to Beightol U.S. Pat. No. 3,421,501, issued on Jan. 14, 1969, the disclosure of which is expressly incorporated herein by reference. In the specific examples set forth in the Beightol Patent, the resin is essentially dry and curable by exposure to ultra-violet light.

In the preferred embodiment of the present invention, the inner protective sleeve 10 is fabricated from non-wetting, polymeric yarns formed into a relatively open and resilient knit fabric. In FIG. 1, the sleeve is shown in the form of a stockinet which has been slit along one edge to provide an opening for the thumb, and then slipped over the forearm of the patient.

For purposes of illustrating typical fabric constructions which may be employed in sleeve 10, FIG. shows a l X 1 half cardigan weft knit fabric 40 comprising a plurality of courses 42 and which has the desired elasticity or resilience, and also sufficient body to provide the required softness of hand. FIG. 6 illustrates a warp knit construction 50 which is known in the trade as Milanese fabric, and which has also been found to be suitable for present purposes. In the Milanese construction, it will be noted that one set of warp threads 52 traverses across the full weft of the fabric in one direction, and a second set of warp threads 54 traverses the full weft in the opposite direction. Each of the above illustrated fabrics may be knit on conventional knitting machines. Obviously, many other suitable fabric constructions could be employed.

It will be appreciated that a relatively large number of materials could be utilized in fabricating the sleeve yarn. However, it has been found that the poly-olefin hydrocarbons such as polyethylene or polypropylene are very satisfactory since they will not absorb water, are essentially chemically inert, and have a high breaking tenacity (i.e., approximately 5 to 7 grams per denier). Also, these polymers have a relatively low melting point (i.e., approximately 250F. to 335F.) which is desirable for the reasons set forth below.

To provide the sleeve fabric with greater body or softness, it is desirable to texturize or bulk the yarn either before or after the knitting operation. In the case of conventional polypropylene yarn, texturizing may be accomplished by a variety of well known methods such as mechanically stretching the yarn or soaking it in hot water.

It is also an aspect of the present invention to utilize a polymeric yarn for the protective sleeve which may be intimately admixed with a bacteriostatic agent such as hexachlorophene, to inhibit the growth and multiplication of micro-organisms. The above poly-olefins are very satisfactory in this regard. Reference is made to the patent to Dubin et al, U.S. Pat. No. 2,919,200 which describes in detail a process for mixing a bacteriostatic agent with various plastic materials, and the disclosure of this patent is expressly incorporated herein.

As pointed out in the Dubin et al patent, the bacteriostatic agent is generally mixed with the plastic resin which is then molded (or extruded through spinnerets and then drawn in the case of yarn formation) at a temperature above the melting point of the agent but below its decomposing or break-down temperature. Thus it is desirable to utilize a plastic material having a low melting point since there is less danger of reaching the break-down temperature of the agent during the molding operation. In the present instance, the bacteriostatic agent is preferably mixed with the polymer either before or during its formation into a yarn.

When both the protective sleeve and outer immobilizing structure are fabricated from non-wetting yarns as indicated above, it will be apparent that the cast will not be degraded by exposure to water and will be quick to dry. Also, when both the sleeve and immobilizing structure are air permeable, ventilating air will be able to pass to the surface of the skin to thereby permit the escape of heat and perspiration, and thus contribute to the comfort of the wearer.

We claim:

1. An immobilizing orthopedic cast characterized by air permeability and non-wettability and thereby permitting air ventilation to the surface of the skin of a wearer and being quick to dry upon exposure to water, said cast comprising,

an inner protective sleeve adapted to be positioned about a portion of the body of a wearer and comprising a relatively open, soft, resilient, air permeable fabric formed of interknit non-wetting, polymeric yarns, and

an outer immobilizing structure surrounding said sleeve and comprising a plurality of superposed, rigid layers of a relatively open, air permeable nonwetting fabric adhered together and including interlaced glass yarns.

2. The orthopedic cast as defined in claim I wherein said sleeve is a tubular stockinet.

3. The orthopedic cast as defined in claim 1 wherein a bacteriostatic agent is intimately admixed with said polymeric yarns.

4. The orthopedic cast as defined in claim 1 wherein said polymeric yarns are textured and comprise polypropylene.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 1 3, 882, 857

INVENTOR(S) Hubert C. Wooda11, Jr.

it is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, after Line 37, add the following paragraph:

In the drawings and specification, there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.

Signed and Scaled this seventh D3,) Of October 1975 [SEAL] A ttest:

RUTH C. MASON ommzssumer ofPatenrs and Trademarks 

1. An immobilizing orthopedic cast characterized by air permeability and non-wettability and thereby permitting air ventilation to the surface of the skin of a wearer and being quick to dry upon exposure to water, said cast comprising, an inner protective sleeve adapted to be positioned about a portion of the body of a wearer and comprising a relatively open, soft, resilient, air permeable fabric formed of interknit non-wetting, polymeric yarns, and an outer immobilizing structure surrounding said sleeve and comprising a plurality of superposed, rigid layers of a relatively open, air permeable non-wetting fabric adhered together and including interlaced glass yarns.
 2. The orthopedic cast as defined in claim 1 wherein said sleeve is a tubular stockinet.
 3. The orthopedic cast as defined in claim 1 wherein a bacteriostatic agent is intimately admixed with said polymeric yarns.
 4. The orthopedic cast as defined in claim 1 wherein said polymeric yarns are textured and comprise polypropylene. 